Heretofore it has been conventional to provide a support frame for receiving and retaining a panel of glass as part of a wall or door assembly. Such a support frame includes an integrally formed body of uniform cross section defining a generally inwardly opening channel as disclosed in, for example, U.S. Pat. No. 4,914,888 in the name of Laurence B. Hanson which granted on Apr. 10, 1990. Screws are inserted through an opening in one side wall of the channel and are threaded into an opening in a second side wall of the channel to draw the two side walls into gripping contact with the glass panel, thus providing a relatively unitized and rigid supporting frame.
Typical also of a frame of this type is such as that disclosed in U.S. Pat. No. 3,363,390 in the name of Jameson Crane granted on Jan. 16, 1968. The frame member in this case is extruded and is folded around a peripheral edge of an associated panel with a screw uniting a single corner of the frame.
More recently it has become conventional to insert a panel in a mold, isolate a peripheral edge portion of the panel and injection mold a polymeric/copolymeric frame about the edge of the panel. Such frames are utilized as front and rear windshields for automobiles or other glass panels for vehicles or buildings, as is reflected in U.S. Pat. No. 4,695,420 granted on Sep. 22, 1986 to Charles E. Grawey et al. and U.S. Pat. No. 4,626,185 granted on Dec. 2, 1986 to Bernard Monnet.
Such injection molded encapsulation is now conventional in shelving, particular for refrigerators, as is evidenced by U.S. Pat. Nos. 5,273,354; 5,362,145; 5,403,084; 5,429,433; 5,441,338 and 5,454,638 issued respectively on Dec. 28, 1993; Nov. 8, 1994; Apr. 4, 1995; Jul. 4, 1995; Aug. 15, 1995 and Oct. 3, 1995, all assigned to the assignee of the present application.
Typically, such shelves are manufactured in an injection mold of the type disclosed in pending application Ser. No. 08/303,200 filed on Sep. 8, 1994 in the names of Max Meier et al. In the latter disclosure a glass plate or panel has its peripheral edge located in a peripheral cavity into which highly pressurized plastic material is injected and, upon subsequent cooling, the edge of the panel is bounded by a polymeric frame or encapsulation which, since intended for use as a refrigerator shelf, has also integrally unitized thereto opposite metallic shelf brackets. A cook top is manufactured similarly in pending application Ser. No. 08/890,651 filed on Jul. 9, 1997.